He announced his decision on Twitter, adding that he has tendered his resignation from the position of spokesperson and not from the PPP.
Khokhar added that he will continue to support the party chairman.
"Will stand by BBZ through thick and thin. In my years as his spokesperson, have given counsel with honesty, sincerity and in the best interests of the country and the party," he wrote on Twitter.
Earlier, reports of his resignation from the party were doing the rounds. But the PPP media cell denied the rumours.